[llvm] [AMDGPU][MC] Disallow null as saddr in flat instructions (PR #101730)

[Jun Wang via llvm-commits]

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@@ -1214,7 +1214,8 @@ class SIInstrInfo final : public AMDGPUGenInstrInfo {
   /// threads in the wave.
   /// \returns The SGPR register that \p SrcReg was copied to.
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jwanggit86 wrote:

Done.

https://github.com/llvm/llvm-project/pull/101730